This invention relates generally to syringe devices and more particularly, but without limitation thereto, to a multiple needled syringe device that permits a simultaneous infusion and withdrawal of one or more substances through a single action.
The prior art contains a variety of devices wherein it is known to use dual needles with either a single or multiple chambered device so as to dispense one or more substances simultaneously through the hollow needles. U.S. Pat. Nos. 4,150,669 and 6,065,371 are illustrative of such designs.
There are however circumstances where it is desirable to inject a substance into an environment while simultaneously permitting a withdrawal of a substance from the environment. Such a scenario exists, for example, in the testing of substances known to pose considerable adverse health effects to human beings and perhaps other life forms. Two such substances may be chemical or biological hazards, wherein leakage of only a very minute amount can wreak deadly havoc.
In laboratory testing or other use of such substances, the substances themselves may be housed within a glass vial having a self-sealing lid or septum over the open end of the glass container. The lid is designed to permit perforation by, for example, a hypodermic needle so that substances can be injected and withdrawn through the safety of the self-sealing lid.
In the aforementioned chemical and biological hazard research field, it has been learned that injection into a vial containing such hazards can produce an undesirable increase in pressure or volume within the vial.
To offset this undesirable pressure or volume increase, injection and withdrawal from the vial has been performed through the use of two separate syringes used at the same time. Such a technique has produced several negative consequences. For one, several syringes are contaminated in the process. In addition, it is challenging to produce substantially equal infusion and withdrawal during this process.
As a consequence, there is a need in the art for a single syringe device that permits simultaneous infusion and withdrawal while preferably being performed via a single action.